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Date: Tue, 18 Oct 2011 14:05:49 +0200
From: "Michael S. Tsirkin" <mst@redhat.com>
Message-ID: <20111018120549.GH28776@redhat.com>
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Subject: Re: [Qemu-devel] [RFC][PATCH 11/45] msi: Factor out delivery hook
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To: Jan Kiszka <jan.kiszka@web.de>
Cc: Alex Williamson <alex.williamson@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, Avi Kivity <avi@redhat.com>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>

On Mon, Oct 17, 2011 at 09:15:47PM +0200, Jan Kiszka wrote:
> On 2011-10-17 15:43, Michael S. Tsirkin wrote:
> > On Mon, Oct 17, 2011 at 11:27:45AM +0200, Jan Kiszka wrote:
> >> diff --git a/hw/msi.c b/hw/msi.c
> >> index 3c7ebc3..9055155 100644
> >> --- a/hw/msi.c
> >> +++ b/hw/msi.c
> >> @@ -40,6 +40,14 @@
> >>  /* Flag for interrupt controller to declare MSI/MSI-X support */
> >>  bool msi_supported;
> >>  
> >> +static void msi_unsupported(MSIMessage *msg)
> >> +{
> >> +    /* If we get here, the board failed to register a delivery handler. */
> >> +    abort();
> >> +}
> >> +
> >> +void (*msi_deliver)(MSIMessage *msg) = msi_unsupported;
> >> +
> > 
> > How about we set this to NULL, and check it instead of the bool
> > flag?
> > 
> 
> Yeah. I will introduce
> 
> bool msi_supported(void)
> {
>     return msi_deliver != msi_unsupported;
> }
> 
> OK?
> 
> Jan
> 

Looks a bit weird ...
NULL is a pretty standard value for an invalid pointer, isn't it?

-- 
MST